Extremely slow debug code about avian HOT 2 CLOSED

To some extent, it's expected that debug mode is over 100 times slower than release mode. This is also the case for Rapier.

You can optimize the debug mode using:

# Optimize just bevy_xpbd_2d (and probably its dependencies?)
[profile.dev.package.bevy_xpbd_2d]
opt-level = 1
# or 2 or 3 depending on how much optimization you want

As for why bevy_rapier's debug mode is faster, I believe bevy_xpbd has a higher default substep count, which gives more accuracy at the cost of performance. Lowering it from 12 to something like 6 or 4 should already give better performance. bevy_xpbd also just hasn't had as much time for optimization yet since we're still missing some quite important features.

For investigating performance, you can use Tracy or flamegraph, see Bevy's profiling docs. We also have a very simple Criterion benchmark for spawning a bunch of cubes, but that won't show how long individual systems take.

from avian.

Thanks for reply.
I tried:

[profile.dev.package.bevy_xpbd_2d]
opt-level = 3

This is enough for development, I got 20 fps for 20 entities/colliders.

from avian.